The present invention relates generally to a cartridge and a drive unit into which the cartridge is inserted, and more particularly to a prevention of erroneous insertions of the cartridge. Also, the present invention is broadly applicable to the prevention of erroneous insertions of a unit when the unit is inserted into an electronic apparatus for accommodating the unit.
Here, the “erroneous insertion” means that the cartridge is not inserted properly or the cartridge is inserted in a direction other than a predetermined direction, and conceptually includes not only that a type of the cartridge is not proper (e.g., where a type, shape, or size of a medium stored in the cartridge is not proper, and where the cartridge is not original manufacturer's product), but also that cartridge's orientation is not proper (e.g., where the cartridge is inserted back to front and upside down).
Along with the recent spread of multimedia, optical information recorders have attracted attentions, which record a large volume of data with a high density and reproduce them at a fast speed. These optical information recorders may use ROM type disks, such as a CD and a laser disk, that are stamped with information when made, write once type disks, such as a CD-R, that are recordable only once, and RAM type disks that may rewrite and delete data any number of times using a magneto optical recording or a phase change recording. Among these optical information recorders, magneto optical recorders are used in such a field that requires a high transfer rate.
These various optical information-recording disks demand various types of magneto optical recorders having a wide variety of mechanisms. For example, it is necessary to arrange the head section properly so as to correspond to a single-side recording arranging a magnetic head at one side and an optical head at the other side, and a double-side recording arranging optical and magnetic heads at both sides. It is also necessary for the disk cartridge to prepare various types of disk cartridges so as to change a shape of a head insertion portion.
As discussed above, if a new disk cartridge and/or disk drive are created whenever a system having a new function is developed, problems occur in compatibility among disk drives for various disk cartridges and prevention of erroneous insertions.
Therefore, each manufacturer has recently exercised its ingenuity so as to make the system having a new mechanism applicable as it is to the existing system, specifically, by using the same-sized disk cartridge that accommodates a disk with high capacity for existing low-capacity information recorder systems.
In this case, it is necessary for the existing disk cartridge and its drive unit to prepare new disks and information recorders and to prevent erroneous insertions of the disk cartridge so as to solve the compatibility problem.
One of conventional erroneous-insertion-preventing mechanisms keeps unchanged a disk cartridge structure and a disk shape etc., and records an identification mark onto the disk for identification purposes: Then, the drive unit reads the identification mark, identifies an attribute of the disk, and takes a proper step for the disk, such as displaying a disk type and automatically ejecting it if it is not a proper type. Another way is to form an identification hole, etc. directly into the disk cartridge: The drive unit then identifies the hole in a mechanical or optical manner, and takes a similar step for the disk depending upon the presence of the hole.
On the other hand, an alternative means for preventing erroneous insertions into the drive unit is a direct change of the disk cartridge shape. One example of disk cartridge disclosed in Japanese Laid-Open Patent Application No. 64-30068 attempts to prevent erroneous insertions of a disk cartridge for a 3.5-inch floppy disk and a disk cartridge for an optical disk, respectively, by providing the disk cartridge for the floppy disk with a notch at a front left corner of its case, and the disk cartridge case for the optical disk with a notch at a front right corner of its case, with respect to the insertion direction. Then, the drive unit is also provided with convexes that correspond to these notches in a cartridge holder, into which these respective cartridges are inserted.
PCT/US95/13467 (WO96/12285) discloses a system that provides, in a disk drive, a middle surface on the insertion way of the disk cartridge, and a switch that projects from the middle surface, while providing a disk cartridge with a projection at its front surface. When the projection pushes the switch, the middle surface allows the disk cartridge to proceed to the inside of the disk drive.
However, the manner that keeps unchanged the cartridge structure and the recording medium shape requires, before recognizing any erroneous insertion, the cartridge to be completely inserted or located in the drive unit, and then the drive unit to determine the erroneous insertion. Therefore, it disadvantageously takes a while to determine whether an erroneous insertion occurs.
On the other hand, the manners in the above two references also require the cartridge to be inserted into the drive to determine whether an erroneous insertion occurs. Therefore, problems occur in that the cartridge contacts and damages the head mechanism, a disk shutter opening/closing arm, etc. in the drive unit during the insertion of the cartridge. In particular, when a user does not recognize the erroneous insertion and compulsorily shoves the cartridge into the drive unit, the cartridge and the drive unit may possibly get damaged. Moreover, there occurs a problem that the cartridge cannot be ejected from the disk drive after erroneously inserted into the disk drive.